|Publication number||US7628509 B1|
|Application number||US 11/455,121|
|Publication date||Dec 8, 2009|
|Priority date||Jun 16, 2006|
|Publication number||11455121, 455121, US 7628509 B1, US 7628509B1, US-B1-7628509, US7628509 B1, US7628509B1|
|Original Assignee||The United States Of America As Represented By The Secretary Of The Navy|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (11), Classifications (13), Legal Events (3)|
|External Links: USPTO, USPTO Assignment, Espacenet|
The Variable Color LED Optical Source was developed with federal funds and is assigned to the United States Government. Licensing and technical inquiries may be directed to the Office of Patent Counsel, Space and Naval Warfare Systems Center, San Diego, Code 20012, San Diego, Calif., 92152; telephone (619) 553-3001, facsimile (619) 553-3821. Reference Navy Case No. 82962.
Most visible light sources are either blackbody heat-generating sources or monochromatic solid-state sources. A need exists for a solid-state, variable-color optical source.
Throughout the several views, like elements are referenced using like references.
Optical Signals 15, 25, and 35 are each approximately linearly polarized and have vertical and horizontal orthogonal polarization components vλi and hλi, as shown in
Optical signal 45, comprised of orthogonal polarization components vλ2 and hλ1 may be transformed into optical signal 65 by passing through the first half-wave plate 60, which is optically coupled to receive optical signal 45 from the first BSC 40 and optically coupled to emit optical signal 65 to the second BSC 80. Rotation of the first half-wave plate 60 will rotate the polarization orientation of optical signal 45 with respect to the second BSC 80, thus altering the amount of components vλ2 and hλ1 in components vmix and hmix of optical signal 65. For example, if the polarization orientation of optical signal 45 is rotated 45 degrees by the first half-wave plate 60, then component vmix will comprise about equal parts of components vλ2 and hλ1. Optical signal 65 is disposed to enter the second BSC 80 such that component hmix passes through the second BSC 80 to form part of optical signal 85; and component vmix is reflected in a direction orthogonal to optical signal 85 to form part of optical signal 83.
The third LED 30 is disposed to generate optical signal 35, which comprises orthogonal polarization components vλ3 and hλ3. Optical signal 35 may be transformed into optical signal 75, having orthogonal polarization components vλ3mix and hλ3mix, by passing through the second half-wave plate 70, which is optically coupled to the second BCS 80. Rotating the second half-wave plate 70 rotates the polarization orientation of optical signal 35 with respect to the second BSC 80, thus adjusting the percentage of components vλ3 and hλ3 that comprise components vλ3mix and hλ3mix of optical signal 75. Optical signal 75 is disposed to enter the second BSC 80 such that the component vλ3mix is reflected and collimated with component hmix to form optical signal 85; and the component hλ3mix passes through the second BSC 80 and is collimated with component vmix to form excess optical signal 83.
The color of optical signal 85 may “tuned” to be any color in the visible spectrum by selectively rotating the first and second half-wave plates 60 and 70 by desired amounts to alter the relative percentages of primary color wavelengths λ1, λ2, and λ3 in optical signal 85. For example, if the first half wave plate 60 is rotated such that component hmix is composed almost entirely of component hλ1, and if the second half-wave plate 70 is rotated such that component vλ3mix comprises the negligible horizontal orthogonal polarization component hλ3 then the resulting color of optical signal 85 will be the primary color associated with wavelength λ1. In one embodiment, the first BSC 40 may be capable of reflecting at least 96% of orthogonal polarization components vλ1 and vλ2 of optical signals 15 and 25 respectively and transmitting at least 98% of orthogonal polarization components hλ1 and hλ2 of optical signals 15 and 25 respectively. In another embodiment, the second BSC 80 may be capable of reflecting at least 96% of orthogonal polarization components vmix and vλ3mix of optical signals 65 and 75 respectively and transmitting at least 98% of orthogonal polarization components hλ3mix and hmix of optical signals 75 and 65 respectively.
As shown in
From the above description of the LED optical source, it is manifest that various techniques can be used for implementing the concepts of the LED optical source without departing from its scope. Moreover, while the LED optical source has been described with specific reference to certain embodiments, a person of ordinary skill in the art would recognize that changes may be made in form and detail without departing from the spirit and the scope of the LED optical source. The described embodiments are to be considered in all respects as illustrative and not restrictive. It should also be understood that the LED optical source is not limited to the particular embodiments described herein, but is capable of many rearrangements, modifications, and substitutions without departing from the scope of the LED optical source.
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|U.S. Classification||362/235, 362/236, 362/242, 359/639, 359/618|
|International Classification||F21V11/00, G02B27/12, F21V1/00, G02B27/10|
|Cooperative Classification||G02B27/283, G02B27/145|
|European Classification||G02B27/14S, G02B27/28B|
|Jun 16, 2006||AS||Assignment|
Owner name: UNITED STATES OF AMERICA AS REP BY SEC OF THE NAVY
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:SCHEPS, RICHARD;REEL/FRAME:018009/0434
Effective date: 20060615
|Jun 12, 2013||FPAY||Fee payment|
Year of fee payment: 4
|Jun 12, 2013||SULP||Surcharge for late payment|